Fertilizer



T all iuhom. it mayTco ncern UNITED srA-ras PATENT" OFFICE.

Atria-En EUrcEIitsoN' cowLEs, or sEwArmN, NEW JERSEY.

FERTILIZER.

Specification of Letters Patent.

No Drawing. Origihal application filed September 18, 1917, Serial I i'o.192,02 8, Divided arid. this application filed December-21, 19.18.-Serial No. 267,809. Renewed May 11, 1921. Serial No. 468,729.

"Be it'known that I, AL RED a citizen ofthe United States, and residentof Sewaren, in the county of Middlesex and State of New Jersey, haveinvented certain new and useful Improvements in Fertilizers, a ofwhichthe following .is'a specification.

a division of my 10 -My invention relates to fertilizers, and isapplication Serial No. 192,- 02s, filed September 10,191 7. I

.It consists in designedly using variable proportions of" lime andhydratedlsilica containing more than fifteen per cent. of

water of hydration obtained from di-calcium siiicateqto supplydeficiencies oflime and soluble silica required for plant growth. Suchsilica contaming variousamou'nts of water are securable bythe action ofcarbonic acid and other acids. and moisture natural and: artificial. v

My invention further consists in'the inupon various simple andcomplex-silicates,

tention al addition 'or formation of de- 1 signed proportions ofsuchsilicates in the preparation of fertilizer mixtures or sub-' stances,either by the addition ofsuch hydrated silica or such silicates and anacid,

with the intentional design of increasing orsupplying intended amountsof hydrated silica to such mixtures. My invention and discovery furtherembodies adding to soils simple or complex calcium silicates artifiyprepared, of such a quality that the cial carbonic acid of the soilwaters will decompose said compounds or mixtures with a liberation ofhydrated silica of a more" soluble type than those hydrated silicas thatordinarily occur in nature as minerals. The presence of other essentialfertilizers, such as potash, iron oxide, phosphoric. acid and soda insaid complex silicates'is not to be .avoided wherethere is sufiicient'allow ance of calcium oxide or carbonate for. the

,silicain the mixture, so that upon the action of carbonic acid andmoisture, there shall be formed alarge amount of hydrated silica bytheir decomposition when used,

In my invention, any silicates may be i 'used in anyymanner so'astosupply to the soil or fertilizer mixtures designed amounts of availableadded soluble silica. There are certain silicates and mixtures of sili-H. Cow Es,

silicate as a source of soluble hydrated silica Patented Feb. 28, 1922;

is set forth in a pending application, Ser.

nate, leaving an insoluble di-calcium silicate,

plus iron oxide and a variable amount of zeolitic material. The alkalialuminate can be treated by known methods and the alkali metal oxide andalumina separated for .use in their respective arts. The di-calciumsilicate, before being applied as a fertilizer or fertilizerconstituent, should be pulverized or reduced to a finely divided state,say to a size to pass an 80 mesh. The di-calcium silicate will have aporous nature because the alkali-aluminate has been leached away.

from it.

One method of preparing artificial alkalisilico-aluminate from which thedi-c-alcium silicate can be obtained, is carried out by me on a largescale for the obtaining of alumina,

for use in making the metal aluminum.

Clay, salt and carbon are shaped into hollow bricks and subjected in aproper furnace to the action of vapor of water, the result beingal-kali-silico-aluminate bricks and hydrochloric acid. 4 Thealkali-silico-aluminate is .mixed with calcium oxide, or carbonate, in

spar, leucite and the like, and the alkali metal oxide and alumina areobtained in the same manner.

Magnesium carbonate found in limestone is molecularly equivalent tocalcium carbonate. Magnesia .(MgO) is known to act like lime inneutralizing soil acidity. It

seems desirable, however, that magnesia in limestone be not too high inquantity, as

its presence raises the sintering temperature.

Hydrated calcium silicate can be also produced by treating infusorialearth, best when high in water of chemical combination with slacked limeat ordinary temperatures.

Infusorial earths may contain as high as ject thirteen per centrofwater.This reaction does not take place with ground crystalline silica. 'Thus,nativehydrated silica may, by treating with slacked lime and water, pro-.duce calcium silicates suitable for use.

Hydrated silica containing the proper amount of water of hydration maybe applied to deficient soils byadding to the fertilizer mixturedi-calcium silicate containing variable percentages of alkali metaloxide.

and alumina after'the same has been. subed to naturally occurring acidsand moisture. I

I have made comparative plant growth experiments using chemicallyequivalent calcium oxide (CaO) proportions in dicalcium silicate,calcium carbonate, calcium lus hydrated hydrate calciu carbonate m\ ciumhydrate silica. mixed therewith, and ca plus hydrated silica in mixture,in soilsboth exists in all soils that'have been submitted to longcultivation. As said before, my dicalcium silicatg is especially adaptedto increase the value of fertilizers to be used on acid or-neutral soilsdeficient in hydrated silica. I Di-calcium silicate can also be obtainedby treating silicious rocks containing potash whereby the di-calciumsilicate is loaded with quite a quantity of potassium aluminate, withother non-harmful "impurities, and the compound substance procured is.de-

compo'sable by carbonic acid and water, liberating in the soils potash,lime and silica as silica in their skeletonsu fertilizers. This materlalmay also be used alone oradded as a constituent to other fertilizers orfertilizer mixtures.

At the present time, soils from the decomposition of plants and manures"are known to contain hydrated silica, alsgartificial mixtures offertilizers, in many instances, contain it in indefinite amounts as anaccidental impurity. Liebig, 1840, from his investigations of thecomposition of the ashes of ,various plants, thought silica necessary asa plant food.

This resulted in experiments with potassium and sodium silicates tosupply silica to augment the growth of grasses, cereals and plantscontaining Very large percentages of drated double silicates, grading toclay, furnish to soil waters solu- The. "aggregate result of this workhas proven that silica, insoluble form is needed to make up.ihatdeficiency that stitutionof the as ,early as Knop and other plantphysiologists, suc- It 1s now universally assumedthat silica,

clay, zeolites and feldspars in soils, furnish a superabundance ofsilica land therefore its addition as a fertilizer is; unnecessary.These substanc'es and 'nat'ural silicates are so minutely soluble thatthe assumption is unwarranted." By annual repeated growths of vegetationupon uncultivated land, hy-

ble silica. ThlS accumulates and is held by zeolites,-vegetation andhumus, and intime, an abundance of the same is in such soils andfurnishes normal amounts to successive growths. Cultivation withexhaustion of humus and annual removal'oflcrops, ex-- hausts the soilfaster than it is replenished. Figuratively, the sponge has *beenremovedthathas accumulated and retained in sufii--' 'cientamount this materialwhich forms a large partof the natural skeletons of plants. Cultivationalso accelerates this loss through facilitating sub-soil 1 drainage.that soil water solutions in soils on Icultivated lands largely freefrom humus, have become deficient in the quantityof' soluble silica thatis needed for maximum plant growth.

Many suggestions have been made involving the fusion of lime with nativepotash minerals such as occur in granites or potash schists andgreen-sand marls, witha View to render available the potash thereinforfertilizer purposes. In such attempts, it was thought necessary to usepotash min-- erals of high otash content and only sulficient lime toisplace the "molecular weight proportions of potassa that were in theconpot'ash silicates therein. It is now thought that such processes arevalueless. In these attempts, the product secured from, for, instance,potash, feldspar and while slowly de--' E. J. Russel, 1915; Edition,

Thus it is p lime, the designwas to lock the lime in the form of aninsoluble mono-calcium aluminum-silicate, freeing thepotassa (K 0) forsolution. It was not realized that impure feldspars and other potash"mineral silicates mixed with free silica, can be treated preferably atjust their sintering temperature after lar weight proportions of lime toeach singlemolecular weight proportion of silica in the, mixture," andthat after suchv treatment, the actionof carbonic acid and moisture on iL theproduct, will cause the alkali aluminate mixing with twomolecucule' of alumina and ultimately two molecules of silica togetherwith water of chemical combination, the quantity of which inverselyvaries toamarked degree with temperatures to which soil waters arenaturally subjected. These substances are the hydrated feldspars orzeolites of nature. They which comprises heatlng a sillcate contamarepermutites, and when immersed in a mixed solution, like-soil waters, thereciprocally exchange, especially alkali earth metal oxides and alkalimetal oxides, inclusive of ammonia. These exchanges are governed by thelaws of mass action as bearing upon the action of various ions, withvariations of temperatureand variations of the density of differentsolutes. Zeolites are recognized as valuable soil constituents.

I disclaim the use of soluble alkali metal silicates for application tothe soil or to add to fertilizer mixtures as a source of supplyofs'oluble silica. Plant growth experiments, long agoabandoned, madewith them, have led plant physiologists into the error ofconsidering-the soluble types of silica as non-essential in thefert-iliza-tio-nof plants. These old experiments failed for a chemicalreason that has not been recognized in this art,

namely: All soils fertilized, or not,-t'hat are suitable for-plantgrowth, must contain calcium bi-carbonate or a salt of calciunr, Theaction of soluble alkali silicates when in solution and brought incontact with calcium salts, leads to the formation of insolublecompounds formed oflime, alkali metal oxide and silica. When these oldexperiments were made, as the-re was always employed an excess of lime,or lime salt, above that necessary to form this insoluble product,

such insoluble salts formed. Therefore,

when the experimenters thought they were furnishing soluble silica tothe soil water, this silica was being immediately precipitated out andso rendered non-available to their plants. The deductions drawn fromtheir experiments were, therefore, misleading. These deductions havefound their way into the literature of this art. Locking up of thesilica occurs even with clay present,

or with zeolites in the soil, when soluble alkali silicates are used.The silica enters into combination to replace silica that has formerlybeen leached away from zeolites during their slow process of degradationtoday. From these causes the old comparative plant growth experimentsfailed to show the value formation of insoluble minerals.

Having thus fully described my invention and the manner in which it isto be carried out, what I claim, is:

1-. The process of forming a fertilizer,

ing potassium oxide and alumina with two molecules of lime for eachmolecule of silica,

thereby forming a product largely decomposable by the action of waterand carbonic acid with liberation of soluble hydrated silica containingmore than fifteen per cent of water of hydration and adding theresulting product to fertilizers deficient in soluble silica and lime.

2. The process of'increasing the amount of hydrated silica and lime thatmay exist in the soil, which comprises adding to a mixture offertilizermaterials di-calcium silicate adapted to be decomposed by carbonic acidand moisture into carbonate of calcium and "hydra-ted silica containingmore than fifteen per cent of water of hydration.

3. The method of supplying to deficient soilshydrated silica containingmore than fifteen per cent of water of hydration, which comprisessubjecting to naturally occurring acids and moisture di-calciumsilicate-containingvariable percentages of alkali metal oxide andalumina, and adding the same to a fertilizer mixture. I

4. The method of producing a fertilizer or i fertilizer component, whichcomprises sintering silicious rocks containing potash with lime in suchproportions as to form di-calcium silicate containing quite a quantityof potassium aluminate, the compound bein adapted to be decomposed andliberated to the soil Ca-Co, and hydrated silica.

Signed at Sewaren, in the county of Middlesex and State of New Jersey,this 18 day of December, A. D. 1918.

ALFRED HUTQ'HINSON COWLES. f Witnesses ALFRED W. Sonmnr, MARTIN KNoEsEL.

